...It is a compelling tale in itself: how Mr. Krupp became only the seventh Jewish papal knight in history, dubbed by Pope John Paul II in 2000 for persuading American manufacturers to donate $12 million worth of high-tech medical equipment to an Italian hospital.

But the more curious and complicated story is the transformation Mr. Krupp has undergone since. With no previous training or special interest in history, he has emerged as the Vatican’s most outspoken Jewish ally in a heated debate at the crux of tensions between Roman Catholic and Jewish leaders and historians: whether Pope Pius XII, the pontiff during World War II, did as much as he could have to save Jews from the Holocaust...more...